Arguably. Hashrate was chosen as a proxy for compute power (which was chosen as a proxy for time). Compute power (or hashing power, now we have ASICs) is effectively a measure of energy, since the hardware cost gets amortised.

It does lead to the same thing though if you think it through: There's always a constant number of transaction space available in a 10 minute window, which is auctioned off to Bitcoin users and yields a certain sum of unclaimed mining fees. This sum is importantly unrelated to either the current hashrate or the energy efficienc in standing up that hashrate.

As long as the total hashrate is "cheaper" than that, in terms of hardware and electricity costs, there is an economic incentive for somebody to start mining (more) – so somebody will.